Electrode for electrical discharge devices



Sept. 8, 1931. R. E. MlEssE 1,822,361

ELECTRODE FOR ELECTRICAL DISCHARGE DEV-ICS Filed oct. 15. 1928 Patented Sept. 8, 193.1

UNITED STATES PATENT oFF-Ict:

RICHARD E. MIFASSE, F CHICGO, ILLINOIS, ASSIGNOR T0 Q. R. DE VRY CORPORATION,

OF CHICAGO, ILLINOIS, A CORPORATION .OF ILLINOIS ELECTRODE FOR ELECTRICAL DISCHARGE DEVICES Application led October 13, 1928. Serial No. 312,302.

My invention relates to a process for preparing gaseous conduction tubes for operation and use in connection with thecarrying out of said process.

My invention contemplates 'in its `preferred form the deposit upon the interior wall of an evacuated tube of a metallic film, which during the operation of the tube, is of use for various purposes, such for instance as the reduction of the cathode drop and the absorption of foreign gases.

In the form ofthe invention as illustrated lherein, the film consists lof metallic'potassium. Potassium as is wl known, cannot be readily handled because of its ainity for oxygen, water vapor and the like. For this reason, I introduce the potassium into the evacuated tube and this introduction is accomplished by forcing a'salt of potassium into a container which serves at the same time as the electrode of the device. Intermingled with this potassium salt is a reducing agent. l

After the introduction of -these elements tube and the removal of occluded ases, the electrode is subjected to bom ardment whereby it is heated. Due to this heating the potassium salt is reduced and the potassium escapes through an outlet provided in said. electrode and is deposited upon the walls of the tube. The tube is rovided with a filling of gas which present y during the operation of the tube will be rendered luminous. A

I will describe my invention more in detail by referring to the accompanying drawing which illustrates one embodiment which my invention may take, the same being fragmentarily shown as a longitudinal section of a gaseous conduction device. v

In'the drawing I show a glass 'tube 10 having the inturned stem 11 through which the conductor 12 passes, this conductor furnishing a current to the electrode which will be presently described. The glass stem l1 is surmounted by a lava bushing 13.

My improved electrode 14 is formed in the shape of a cylindrical container and has an 50 outlet opening 15. This container is screwthreaded at its open extremity and at this extremity has screwthreaded engagement vwith a closure or cap element 16. The cap 16 has screwthreaded engagement with the inner extremity of theconductor 12, thus establishing an electrical continuity between the conductor 12 and the electrode 14. Be-A ture consisting of potassium vchloride andcerium and pack the same in position preferably under pressure byV means of the cap 17. The electrode with the filling andthe A other parts thus far described are' mounted as shown in the illustration, whereafter the tube is entirely evacuated and the occluded gases removed.

Thereupon the electrode 14 is heated preferably by bombardment action and this heating heats the potassium chloride and the cerium with the 'result that 'potassium is glven olf and cerium chloride remains. The

' chemical action which takes place is as follows z-3Kc1 Cle- CeCl3 -I- 3K. 25 and after the thorough evacuation of the The free potassium passes through the outlet 15 and deposits itself on the walls of the glass surrounding -the electrode. When the proper gas filling is supplied to the interior of the tube, the tube is then ready for operation. During operation, the tube becomes rheated but this heating alone as a general rulev is not sucient to bring about the reaction as heretofore described which occurs when the electrode 14 is heated to a higher temperature. During thenormal operation of the tube, however, the deposited potassium becomes vaporized, thuslovvering the cathodedrop and -also assisting in cleaning up any obnoxious or foreign gases whichmay be present.

From what has thus been described,

'inn

the combination with a vacuous tube, of a hollow electrode therein adapted to serve as a container and having an outlet', an insulating support for said electrode enclosing one end thereof, said electrode being adapted when heated to permit contents thereof to be deposited upon the tube wall, and means extending exteriorly of said tube for conducting current to said electrode.

2. In. a devicey of the character described the combination with a vacuous tube, of a hollow electrode therein adapted to serve as a container and having an open end and outlet, an insulatin support for said electrode, a closure for sai open end seated in said insulating support, said electrode being ada ted When heated to permit contents thereo to be deposited upon the tube Wall, and means extending exteriorly of said tube for conducting current to said electrode.

In witness whereof, I hereunto subscribe my name this 2nd day of October, A. D. 1928.

RICHARD E. MIESSE. 

